Polymers of olefins are important items of commerce, and these polymers are used in a myriad of ways, from low molecular weight polyolefins being used in lubricants and waxes, to higher molecular weight grades being used for fiber, films, molding resins, elastomers, etc.
Olefins may be polymerized by a variety of transition metal containing catalysts, for example metallocene and Ziegler-Natta type catalysts. More recently, other types of transition metal containing polymerization catalysts have been discovered, in which the transition metal atom is complexed to a neutral or monoanionic ligand. See, for instance, U.S. Pat. No. 5,714,556, U.S. Pat. No. 5,880,241, U.S. Pat. No. 6,060,569, U.S. Pat. No. 6,174,975, WO 9842664 and WO 9842665, all of which are incorporated by reference herein for all purposes as if fully set forth. Each type of polymerization catalyst has its advantages and disadvantages, and due the commercial importance of polyolefins, new polymerization catalysts are constantly being sought.